Inhomogeneous baryogenesis, cosmic antimatter, and dark matter

A model of inhomogeneous baryogenesis based on the Affleck and Dine mechanism is described. A simple coupling of the scalar baryon field to the inflaton allows for formation of astronomically significant bubbles with a large baryon (or antibaryon) asymmetry. During the farther evolution these domains form compact stellar-like objects, or lower density clouds, or primordial black holes of different size. According to the scenario, such high baryonic number objects occupy relatively small fraction of space but despite that they may significantly contribute to the cosmological mass density. For some values of parameters the model allows the possibility the whole dark matter in the universe to be baryonic. Furthermore, the model allows the existence of the antibaryonic B-bubbles, i.e. a significant fraction of the mass density in the universe can be in the form of the compact antimatter objects (e.g. antistars). (C) 2008 Elsevier B.V. All rights reserved.